Sample measurement apparatus and method of measuring samples

ABSTRACT

A sample measurement apparatus according to one or more embodiments includes a processing unit that aspirates a sample inside a sample container and measures the sample; a transfer unit that includes a holder to hold the sample container, and that picks up the sample container from a rack capable of storing the sample containers at storage positions on a row and transfers the sample container to the processing unit; and a detection unit that is attached to the holder and is movable integrally with the holder, and that detects whether or not there is the sample container at each of the storage positions.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of InternationalApplication No. PCT/JP2015/081532, filed on Nov. 10, 2015, entitled“SAMPLE MEASUREMENT APPARATUS AND METHOD OF MEASURING SAMPLES”, whichclaims priority based on the Article 8 of Patent Cooperation Treaty fromprior Japanese Patent Applications No. 2014-232239, filed on Nov. 14,2014, the entire contents of which are incorporated herein by reference.

BACKGROUND

This disclosure relates to a sample measurement apparatus and a methodof measuring samples.

There is a sample measurement apparatus which picks up a samplecontainer from a holding stand capable of holding multiple samplecontainers and transfers the sample container to a processing unit. Forexample, in a specimen analysis apparatus described in Japanese PatentApplication Publication No. 2007-139463 (Patent Literature 1), a holderholds a specimen container set on a holding stand and transfers thespecimen container thus held to an agitation position. When a sensordetects that the specimen container is being held by the holder beforereaching the agitation position, the specimen container is turned overfor agitation, and set on a specimen setting part. Then, an aspirationunit aspirates a specimen inside the specimen container. If the holderis not holding a specimen container, the holder picks up anotherspecimen container at a different position.

SUMMARY

A sample measurement apparatus according to one or more embodiments mayinclude: a processing unit that aspirates a sample inside a samplecontainer and measures the sample; a transfer unit that includes aholder to hold the sample container, and that picks up the samplecontainer from a rack capable of storing the sample containers atstorage positions on a row and transfers the sample container to theprocessing unit; and a detection unit that is attached to the holder andis movable integrally with the holder, and that detects whether or notthere is the sample container at each of the storage positions.

A method of measuring samples according to one or more embodiments mayinclude: causing a holder for holding a sample container to move to apoint above a first storage position on a rack capable of storing thesample containers at storage positions on a row; causing a detectionunit that is attached to the holder and is movable integrally with theholder to detect whether or not there is the sample container at thefirst storage position; if the detection unit located at a point abovethe first storage position detects that there is the sample container atthe first storage position, causing the transfer unit to transfer thesample container from the first storage position to a measurement unit;and if the detection unit located at the point above the first storageposition detects that there is no sample container at the first storageposition, directly sending the holder from the point above the firststorage position to a point above a second storage position arranged onthe same row as the first storage position, and causing the detectionunit to detect whether or not there is the sample container at thesecond storage position.

A sample measurement apparatus according to one or more embodiments mayinclude: a measurement unit that measures a sample in a samplecontainer; a holder that moves between the measurement unit and storagepositions on a rack at which the sample containers are stored and thatpicks up and holds the sample container stored at one of the storagepositions; a transfer unit that transfers the sample container held bythe holder to the measurement unit; and a detection unit that is movableintegrally with the holder while keeping a relative positionalrelationship between the detection unit and the holder, and that detectswhether or not there is the sample container at each of the storagepositions.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram illustrating a configuration of a samplemeasurement apparatus according to one or more embodiments;

FIGS. 2A and 2B are diagrams illustrating external appearances of asample container and a rack according to one or more embodiments,respectively, and FIG. 2C is a diagram illustrating an externalappearance of the sample measurement apparatus according to one or moreembodiments;

FIG. 3 is a schematic diagram of the inside of a housing of the samplemeasurement apparatus according to one or more embodiments when viewedfrom above;

FIGS. 4A and 4B are diagrams of a holder according to one or moreembodiments when viewed in a negative X-axis direction;

FIG. 5A is a schematic diagram of the holder according to one or moreembodiments when viewed in the negative X-axis direction, and FIG. 5B isa schematic diagram of a holder according to a modified example whenviewed in the negative X-axis direction;

FIG. 6 is a flowchart illustrating processing by the sample measurementapparatus according to one or more embodiments;

FIG. 7 is a flowchart illustrating an initialization operation accordingto one or more embodiments;

FIG. 8 is a flowchart illustrating processing on the rack according toone or more embodiments;

FIG. 9 is a flowchart illustrating processing on the rack according toone or more embodiments;

FIGS. 10A and 10B are flowcharts illustrating measurement processing andanalysis processing according to one or more embodiments, respectively;and

FIGS. 11A to 11C are scattergrams respectively illustrating results ofDIFF measurement, RET measurement, and PLT measurement according to oneor more embodiments.

Note that the drawings are devoted to explanation and do not limit thescope of the invention.

DETAILED DESCRIPTIONS

Embodiments are explained with reference to drawings. In the respectivedrawings referenced herein, the same constituents are designated by thesame reference numerals and duplicate explanation concerning the sameconstituents is basically omitted. All of the drawings are provided toillustrate the respective examples only. No dimensional proportions inthe drawings shall impose a restriction on one or more embodiments. Forthis reason, specific dimensions and the like should be interpreted withthe following descriptions taken into consideration. In addition, thedrawings may include parts whose dimensional relationship and ratios aredifferent from one drawing to another.

One or more embodiments to be described later are directed to anapparatus which detects blood cells and the like contained in a bloodsample stored in a sample container and performs blood-related tests andanalysis. Note that one or more embodiments are applicable to anapparatus which performs processing on a blood sample stored in a samplecontainer, and that the sample to be processed may be other than a bloodsample.

As illustrated in FIG. 1, sample measurement apparatus 10 includescontroller 11, transfer unit 12, detection unit 13, processing unit 14,pneumatic pressure source 15, mechanism unit 16, sensor unit 17, andinput-output unit 18. The units of sample measurement apparatus 10except for input-output unit 18 are housed in housing 21 illustrated inFIG. 2C. Sample measurement apparatus 10 also includes drawers 31illustrated in FIG. 3. Rack 200, which can store sample containers 100in rows, is set on each of drawers 31.

As illustrated in FIG. 2A, sample container 100 includes body part 101and cover part 102. Body part 101 is a tubular container and has anopening formed in an upper end thereof. Body part 101 houses a sample,and the opening in the upper end of body part 101 is sealed with coverpart 102.

As illustrated in FIG. 1 and FIG. 2B, rack 200 includes ten storagesections 201 formed for holding sample containers 100 vertically. FIG. 1and FIG. 2B each illustrate coordinate axes of FIG. 3 when racks 200 areset on drawers 31. Hereinafter, positions of ten storage sections 201are referred to as storage positions 211 to 220. Storage positions 211to 215 are arranged in an X-axis direction on the negative Y-axis sideof rack 200, while storage positions 216 to 220 are arranged in theX-axis direction on the positive Y-axis side of rack 200. In rack 200,the number of rows of the storage positions provided may be one, orthree or more.

Back to FIG. 1, controller 11 receives signals outputted by the units ofsample measurement apparatus 10, and controls the units of samplemeasurement apparatus 10. Transfer unit 12 includes holder 12 a. Holder12 a holds sample container 100. Transfer unit 12 picks up samplecontainers 100 from rack 200 using holder 12 a, and transfers the samplecontainers to processing unit 14. Detection unit 13 is integrally andmovably attached to holder 12 a. Detection unit 13 moves integrally withholder 12 a while keeping a relative positional relationship betweenDetection unit 13 and holder 12 a. Detection unit 13 includes operatingunit 13 a and detector 13 b illustrated in FIG. 4A, and detects whetheror not there are sample containers 100 at storage positions 211 to 220.

Processing unit 14 performs processing on samples inside samplecontainers 100. Processing unit 14 includes agitation unit 14 a andmeasurement unit 14 b. Agitation unit 14 a performs an agitationoperation on sample containers 100. Measurement unit 14 b aspirates thesamples inside sample containers 100 and performs measurement on thesamples. Transfer unit 12 transfers sample containers 100 from rack 200to measurement unit 14 b via agitation unit 14 a. Pneumatic pressuresource 15 sends out air to and sucks in air from the units in samplemeasurement apparatus 10 which operate using air. Mechanism unit 16includes other mechanisms of sample measurement apparatus 10. Sensorunit 17 includes sensors installed inside sample measurement apparatus10. Input-output unit 18 receives an input by an operator and outputsinformation. Input-output unit 18 is a touch-panel-type display.

With reference to FIG. 1, a description of provided for an overview ofprocessing to transfer sample container 100.

Controller 11 causes transfer unit 12 to transfer multiple samplecontainers 100 stored on rack 200 in a predetermined order. To be morespecific, controller 11 causes transfer unit 12 to pick up multiplesample containers 100 stored at storage positions 211 to 220 of rack 200in the order of storage positions 211 to 220, and to transfer picked-upsample containers 100.

When controller 11 sets a first storage position as a transfer target,controller 11 moves holder 12 a to a point above the first storageposition, and causes detection unit 13 to detect, at a point above thefirst storage position, whether or not there is sample container 100 atthe first storage position. If there is sample container 100 at thefirst storage position, controller 11 causes transfer unit 12 totransfer sample container 100 from the first storage position toprocessing unit 14. If there is no sample container 100 at the firststorage position, controller 11 sets a second storage position, which isarranged on the same row as that of the first storage position and isnot yet set as the transfer target, as the transfer target. To be morespecific, if the first storage position is any one of storage positions211 to 214 and 216 to 219, the second storage position is a storageposition located next to the first storage position in the negativeX-axis direction. In such a case, controller 11 sends holder 12 adirectly to a point above the second storage position from a point abovethe first storage position, and causes detection unit 13 to detectwhether or not there is sample container 100 at the second storageposition.

If there is no second storage position in a first row containing thefirst storage position, controller 11 sets a predetermined storageposition in a second row different from the first row as the secondstorage position. To be more specific, if the first storage position isstorage position 215, there is no storage position yet to be set as thetransfer target in the first row, i.e., the row of storage positions 211to 215 containing storage position 215. Thus, second storage position isset to storage position 216 in the second row, i.e., the row of storagepositions 216 to 220 different from the row containing storage position215. In this case, controller 11 sends holder 12 a to a point above thesecond storage position from a point above the first storage position,and causes detection unit 13 to detect whether or not there is samplecontainer 100 at the second storage position.

If the first storage position is storage position 220 and there is nosample container 100 at the first storage position, this means thatinitial tests on all sample containers 100 held on rack 200 havefinished. After that, retests on sample containers 100 held on rack 200are performed when needed, and processing on rack 200 is terminated.Detailed description on the processing to transfer sample containers 100is provided later with reference to flowcharts.

As illustrated in FIG. 2C, a front surface housing 21 includes twopanels 22, power button 23, and start button 24. In the case ofmeasurement of a sample, an operator turns on sample measurementapparatus 10 by pressing power button 23. Drawer 31 illustrated in FIG.3 is connected to each of two panels 22 on the positive Y-axis side. Theoperator draws drawers 31 toward the negative Y-axis side by pullingpanels 22 toward the negative Y-axis side. The operator sets racks 200,holding sample containers 100, on drawers 31. The operator pushes panels22 toward the positive Y-axis side and presses start button 24 to startprocessing on sample containers 100.

As illustrated in FIG. 3, housing 21 has transfer unit 12, agitationunit 14 a, measurement unit 14 b, two drawers 31, container set unit 32,piercer 33, and two lock units 40 installed therein. Measurement unit 14b includes piercer 33, specimen preparation unit 34, and detector 35.Controller 11, detection unit 13, mechanism unit 16, and sensor unit 17are also installed inside housing 21, but their illustration is omittedfor convenience. As illustrated in FIG. 3, a positive X-axis directionis a rightward direction, a positive Y-axis direction is a rearwarddirection, and a positive Z-axis direction is an upward direction.

Two drawers 31 are arranged on the left and right. Each of panels 22 isconnected to an end portion in the front of corresponding drawer 31.When the operator moves panels 22 in a front-rear direction, drawers 31move in the front-rear direction together with panels 22. Each drawer 31has a hollow portion formed approximately at a center thereof, to whichrack 200 can be detachably attached. A not-illustrated sensor isinstalled to the hollow portion, and this sensor detects whether or notrack 200 is set on drawer 31. Rack 200 is not necessarily attachable toand detachable from drawer 31. Instead, rack 200 may be fixed to drawer31 in advance. A not-illustrated sensor is installed in the rear of eachdrawer 31 pushed to the rear, and this sensor detects whether or notdrawer 31 is pushed to the rear.

Each of lock units 40 includes rod member 41 and hole member 42. Rodmember 41 is provided to each drawer 31, and hole member 42 is installedinside housing 21. When processing on rack 200 set on drawer 31 is to beperformed, drawer 31 is locked so that rack 200 is not erroneously drawntoward the front. To be more specific, rod member 41 provided to drawer31 is driven by a not-illustrated drive unit in the X-axis direction,and is inserted into a hole formed in hole member 42. Thus, the drawingof individual drawers 31 arranged on the left and right is regulated.Also, when rod member 41 is driven in the direction opposite to that inthe case of locking drawer 31, drawer 31 is unlocked so that drawer 31can be drawn in a negative Y-axis direction.

Transfer unit 12 includes motors 51 and 52, belts 53 and 54, and moveunit 60. Move unit 60 includes left-right move unit 61, front-rear moveunit 62, and holder 12 a. Each of motors 51 and 52 is a stepping motor.

Left-right move unit 61 moves in the left-right direction while beingsupported by a not-illustrated guide which is provided inside housing 21and extends in the left-right direction. Motor 51 drives belt 53 woundaround pulleys, disposed on the left and right inside housing 21, in theleft-right direction. Fixed to belt 53 is attachment piece 61 a ofleft-right move unit 61. Thus, left-right move unit 61 is allowed tomove in the left-right direction in conjunction with belt 53.

Front-rear move unit 62 moves in the front-rear direction while beingsupported by a not-illustrated guide which is provided to left-rightmove unit 61 and extends frontward and rearward. Motor 52 drives belt 54wound around pulleys, disposed on the left and right inside housing 21,in the left-right direction. Portions of belt 54 are bent forward atpulleys 61 b provided to left-right move unit 61, and a portion of belt54 is wound around pulley 61 c provided in the front of left-right moveunit 61. Attachment piece 62 a of front-rear move unit 62 is attached toa portion of belt 54 between pulley 61 c and one of pulleys 61 b. Thus,front-rear move unit 62 is allowed to move in the front-rear directionin conjunction with belt 54.

Holder 12 a is supported by front-rear move unit 62 through cylinder 62b of front-rear move unit 62. When cylinder 62 b is driven, holder 12 amoves in a Z-axis direction. Holder 12 a includes hands 301 and 302.Holder 12 a grasps sample container 100 by driving hands 301 and 302 ina direction of approaching each other and a direction of receding fromeach other.

Transfer unit 12 configured as above allows hands 301 and 302 to freelymove in the X-, Y-, and Z-axis directions inside housing 21. Thus,sample containers 100 are grasped by hands 301 and 302, and are freelytransferred in the X-, Y-, and Z-axis directions inside housing 21. Adetailed configuration of holder 12 a is described later with referenceto FIGS. 4A and 4B and FIG. 5A.

Installed inside housing 21 are not-illustrated through-beam sensors fordetecting that left-right move unit 61 is positioned at a leftmost endor a rightmost end. Installed to left-right move unit 61 is anot-illustrated through-beam sensor for detecting that front-rear moveunit 62 is positioned at a rearmost point. Using detection signals ofthese sensors and the number of steps of each of motors 51 and 52,controller 11 can acquire positions of hands 301 and 302 in an X-Yplane. In addition, installed to front-rear move unit 62 is anot-illustrated through-beam sensor for detecting that holder 12 a ispositioned at a lowermost point.

Agitation unit 14 a includes motor 71, shaft 72, and contact member 73.Shaft 72 extends in the front-rear direction, and an end portion in therear of shaft 72 is connected to motor 71. Contact member 73 is fixed toan end portion in the front of shaft 72.

When hands 301 and 302 of holder 12 a pick up sample container 100 fromrack 200 and position the sample container at position 81, motor 71turns contact member 73 through shaft 72. This causes contact member 73to push hand 301 from the negative X-axis side and thus hand 301 to turnover sample container 100 positioned at position 81 to agitate thesample inside sample container 100. To return sample container 100 to avertical state, motor 71 turns contact member 73 through shaft 72 in theopposite direction. Thus, contact member 73 is detached from hand 301,and hands 301 and 302 grasping sample container 100 are returned to thevertical state due to their own weights.

When agitation unit 14 a finishes with agitation processing at position81, transfer unit 12 sets sample container 100 on container set unit 32positioned at position 82. Sample container 100 is transported toposition 83 by container set unit 32. When sample container 100 ispositioned at position 83, piercer 33 aspirates the sample from samplecontainer 100.

When the aspiration of the sample finishes, container set unit 32transports sample container 100 forward to position the sample containerat position 82. After that, sample container 100 is returned to theoriginal storage position in original rack 200 by transfer unit 12. Asdescribed above, sample containers 100 held on rack 200 are picked up insequence, and piercer 33 aspirates the samples therein.

Sample containers 100 are transferred as described above so that rack200 on the opposite side of rack 200 to be processed is not preventedfrom being drawn. To be more specific, in the X-Y plane, samplecontainer 100 is transferred such that hands 301 and 302 do not enter aregion of rack 200 on the opposite side of rack 200 to be processed anda region in front of rack 200 on the opposite side of rack 200 to beprocessed. Thus, the operator is allowed to draw drawer 31 on theopposite side of drawer 31 on which rack 200 to be processed is set, andto set rack 200 on this drawer 31.

The sample aspirated by piercer 33 is transferred to specimenpreparation unit 34. Specimen preparation unit 34 prepares a measurementspecimen by mixing the sample and a reagent. The measurement specimen isallowed to flow into flow cell 35 a of detector 35. Detector 35irradiates the measurement specimen flowing through flow cell 35 a witha laser beam, and receives, using a photodetector, light produced fromparticles contained in the measurement specimen. Controller 11 analyzesthe sample based on an output signal of the photodetector, and displaysthe analysis results on input-output unit 18.

As illustrated in FIG. 4A, holder 12 a includes hands 301 and 302 andopen-close mechanism 310. Formed at lower ends of hands 301 and 302 arefirst claw 301 a and second claw 302 a, respectively. Hands 301 and 302use first claw 301 a and second claw 302 a to grasp sample container100. Open-close mechanism 310 includes substrate 311, belt 312, shaft313, spring 314, members 315 to 317, and cylinder 318. Open-closemechanism 310 opens and closes hands 301 and 302. Detection unit 13includes operating unit 13 a and detector 13 b.

Substrate 311 is moved in the Z-axis direction by cylinder 62 billustrated in FIG. 3. Belt 312 is wound around pulleys disposed on thepositive Y-axis side and the negative Y-axis side of substrate 311.Shaft 313 is fixed to substrate 311. Hands 301 and 302 are installed onshaft 313 so as to be turnable around shaft 313 as the center of turn.Spring 314 is interposed between hands 301 and 302. Spring 314 applies aforce to hands 301 and 302 in a direction of extending the distancebetween hands 301 and 302.

Two surfaces parallel to an X-Z plane are formed on member 315, and hand301 is sandwiched by these two surfaces. Attachment piece 315 a ofmember 315 is fixed to a lower portion of belt 312. Member 316 is fixedto an upper end of member 315. Operating unit 13 a is installed on theupper side of an end portion on the negative Y-axis side of member 316.Operating unit 13 a is a plate-shaped member parallel to a Y-Z plane.Two surfaces parallel to the X-Z plane are formed on member 317, andhand 302 is sandwiched by these two surfaces. Attachment piece 317 a ofmember 317 is fixed to an upper side portion of belt 312. Detector 13 bis installed on an upper end of member 317. Detector 13 b is athrough-beam sensor including a light emitter and a light receiver. Thelight emitter and the light receiver of detector 13 b are arranged inthe X-axis direction.

Cylinder 318 is fixed to substrate 311. An end portion on the negativeY-axis side of rod 318 a of cylinder 318 is fixed to member 317.

When cylinder 318 is supplied with a negative pressure in the state ofFIG. 4A, rod 318 a moves in the positive Y-axis direction. This causesmember 317, hand 302, and detector 13 b to move in the positive Y-axisdirection. At that moment, attachment piece 317 a moves in the positiveY-axis direction. For this reason, the upper side of belt 312 moves inthe positive Y-axis direction, and the lower side of belt 312 moves inthe negative Y-axis direction. Thus, members 315 and 316, hand 301, andoperating unit 13 a move in the negative Y-axis direction. As a result,when cylinder 318 is supplied with a negative pressure in the state ofFIG. 4A, first claw 301 a and second claw 302 a approach each other, andoperating unit 13 a and detector 13 b approach each other.

After cylinder 318 is supplied with a negative pressure in the state ofFIG. 4A and then cylinder 318 is supplied with a positive pressure, rod318 a moves in the negative Y-axis direction. This causes member 317,hand 302, and detector 13 b to move in the negative Y-axis direction. Atthat moment, attachment piece 317 a moves in the negative Y-axisdirection. For this reason, the upper side of belt 312 moves in thenegative Y-axis direction, and the lower side of belt 312 moves in thepositive Y-axis direction. Thus, members 315 and 316, hand 301, andoperating unit 13 a move in the positive Y-axis direction. As a result,after cylinder 318 is supplied with a negative pressure in the state ofFIG. 4A and then cylinder 318 is supplied with a positive pressure,first claw 301 a and second claw 302 a recede from each other, andoperating unit 13 a and detector 13 b recede from each other.

As described above, open-close mechanism 310 opens and closes hands 301and 302 to move first claw 301 a and second claw 302 a. Operating unit13 a is integrally attached to hand 301 with members 315 and 316 inbetween, and moves together with the open-close operation of hand 301.Detector 13 b is integrally attached to hand 302 with member 317 inbetween, and moves together with the open-close operation of hand 302.Thus, operating unit 13 a moves together with the open-close operationof first claw 301 a, and detector 13 b moves together with theopen-close operation of second claw 302 a.

Next, a description is provided for the grasping of sample containers100 and detection as to whether or not there are sample containers 100.When sample container 100 is to be grasped and detection is to be madeas to whether or not there is sample container 100, holder 12 a ispositioned above the storage position of the transfer target while hands301 and 302 are in an open state, as illustrated in FIG. 4A.

If there is sample container 100 at the storage position when cylinder318 is supplied with a negative pressure above this storage position ofthe transfer target while in the state of FIG. 4A, first claw 301 a andsecond claw 302 a grasp sample container 100, as illustrated in FIG. 4B.At that moment, a position of operating unit 13 a and a position ofdetector 13 b do not overlap each other in the Y-Z plane. Thus,controller 11 can determine that there is sample container 100 at thestorage position of the transfer target based on the fact that cylinder318 was supplied with a negative pressure and detector 13 b does notdetect operating unit 13 a. After rod 318 a moves in the negative Y-axisdirection while in the state of FIG. 4B, hands 301 and 302 are returnedto the state of FIG. 4A. As a result, the grasping of sample container100 is released.

The grasping force of sample container 100 is strengthened in the casewhere sample container 100 is grasped after cylinder 318 is suppliedwith a negative pressure compared to the case where sample container 100is grasped after cylinder 318 is supplied with a positive pressure.Thus, it is possible to reliably grasp sample container 100.

If there is no sample container 100 at the storage position whencylinder 318 is supplied with a negative pressure above this storageposition of the transfer target while in the state of FIG. 4A, hand 301and hand 302 are closed to have a width smaller than that of samplecontainer 100, as illustrated in FIG. 5A. Here, operating unit 13 a ispositioned at a detection position of detector 13 b. To be morespecific, the position of operating unit 13 a and the position ofdetector 13 b overlap each other in the Y-Z plane, and operating unit 13a is positioned between the light emitter and the light receiver ofdetector 13 b. Thus, controller 11 can determine that there is no samplecontainer 100 at the storage position of the transfer target based onthe fact that detector 13 b detects operating unit 13 a.

Since the opening and closing of hands 301 and 302 is detected whenoperating unit 13 a interrupts the beam emitted from the light emitterof detector 13 b, it is possible to detect, with a simple configuration,whether or not there is sample container 100. Since sample container 100is detected by operating unit 13 a and detector 13 b which areconfigured to move together with the open-close operation of first claw301 a and second claw 302 a, respectively, it is possible to morereliably detect whether or not there is sample container 100 compared tothe case where a through-beam sensor installed on substrate 311 detectswhether or not there is sample container 100.

Holder 12 a may be configured as illustrated in FIG. 5B. In such a case,hand 301 and member 315 are installed on shaft 313 so as not to move inthe Y-axis direction. Belt 312 and member 316 are omitted. Spring 314applies a force to hands 301 and 302 in a direction of shortening thedistance between hands 301 and 302. Operating unit 13 a is installed onthe upper end of member 317, and detector 13 b is installed on substrate311.

When cylinder 318 is supplied with a negative pressure in the state ofFIG. 5B, rod 318 a moves in the positive Y-axis direction. This causesmember 317, hand 302, and operating unit 13 a to move in the positiveY-axis direction. In this case as well, operating unit 13 a is notpositioned between the light emitter and the light receiver of detector13 b if there is sample container 100 between first claw 301 a andsecond claw 302 a. Operating unit 13 a is positioned between the lightemitter and the light receiver of detector 13 b if there is no samplecontainer 100 between first claw 301 a and second claw 302 a. Thus, itis possible to detect whether or not there is sample container 100 atthe storage position of the transfer target.

In holder 12 a illustrated in FIG. 5B, the position in the Y-axisdirection of hand 301 is fixed. For this reason, when hands 301 and 302are to grasp sample container 100, hand 301 is driven in the positiveY-axis direction and, in addition, holder 12 a is driven in the negativeY-axis direction. Thus, both of hands 301 and 302 move to grasp samplecontainer 100. As described above, in the configuration illustrated inFIG. 5B, it is necessary to drive not only hand 302 but also holder 12 ain order to grasp sample container 100. Hence, the configuration ofholder 12 a illustrated in FIGS. 4A and 4B and FIG. 5A makes it possibleto easily control the grasping operation of sample container 100compared to the configuration of holder 12 a illustrated in FIG. 5B.

In holder 12 a illustrated in FIGS. 4A and 4B and FIG. 5A, detector 13 bmay be installed on member 316, and operating unit 13 a may be installedon member 317. In holder 12 a illustrated in FIG. 5B, detector 13 b maybe installed on the upper end of member 317, and operating unit 13 a maybe installed on substrate 311.

In holder 12 a illustrated in FIGS. 4A and 4B and FIG. 5A and in holder12 a illustrated in FIG. 5B, detector 13 b may be a reflective sensor.Alternatively, detector 13 b may be a push-button sensor. If detector 13b is a push-button sensor, a button of detector 13 b is pushed in byoperating unit 13 a when hands 301 and 302 are closed. Thus, as in thecase of the foregoing discussion, it is possible to detect whether ornot there is sample container 100 at the storage position of thetransfer target.

Next, a description is provided for processing by sample measurementapparatus 10 with reference to a flowchart of FIG. 6. The processingillustrated in FIG. 6 is started when the power of sample measurementapparatus 10 is turned on.

At step S11, controller 11 moves holder 12 a to an initial position. Tobe more specific, controller 11 causes left-right move unit 61 to moveholder 12 a to the leftmost side, causes front-rear move unit 62 to moveholder 12 a to the rearmost side, and causes cylinder 62 b to moveholder 12 a to the uppermost side. When holder 12 a is positioned at theinitial position, hands 301 and 302 are positioned at position 81 in theX-Y plane.

At step S12, controller 11 determines whether or not a start instructionis made by start button 24. When the start instruction is made,controller 11 performs at step S13 an initialization operation fortransfer unit 12 illustrated in FIG. 7.

With reference to FIG. 7, when the initialization operation for transferunit 12 is started, controller 11 determines at step S101 whether or notholder 12 a is at the initial position. To be more specific, controller11 detects with a sensor whether or not left-right move unit 61 ispositioned on the leftmost side, and detects with a sensor whether ornot front-rear move unit 62 is positioned on the rearmost side.Controller 11 determines that holder 12 a is at the initial position ifleft-right move unit 61 is positioned on the leftmost side andfront-rear move unit 62 is positioned on the rearmost side.

If holder 12 a is not at the initial position, controller 11 performsthe initialization operation at steps S102 to S106. If holder 12 a is atthe initial position, controller 11 does not perform the initializationoperation at steps S102 to S106. As described above, it is possible topromptly start the processing at step S14 and the subsequent steps inFIG. 6 if the configuration is such that the initialization operationfor transfer unit 12 is not performed in the case where holder 12 a isat the initial position when the initialization operation for transferunit 12 is to be performed.

At step S102, controller 11 starts an operation to move left-right moveunit 61 to the leftmost side. At step S103, controller 11 starts anoperation to move front-rear move unit 62 to the frontmost side, andthen starts an operation to move front-rear move unit 62 to the rearmostside. Holder 12 a starts moving to the left-rear side through steps S102and S103. The operations started at steps S102 and S103 are performedsuch that hands 301 and 302 do not come into contact with racks 200 andsample container 100.

At step S104, controller 11 determines whether or not hands 301 and 302have moved to the outside of both racks 200 in the X-Y plane after theoperations started at steps S102 and S103. After hands 301 and 302 havemoved to the outside of both racks 200 in the X-Y plane, controller 11starts at step S105 an operation to move holder 12 a to the lowermostside and the uppermost side. Controller 11 detects with a sensor whetheror not holder 12 a is positioned on the lowermost side. Step S105 allowscontroller 11 to acquire the position in an up-down direction of holder12 a, and then to position holder 12 a on the uppermost side.

Note that at step S105, hands 301 and 302 start moving in the up-downdirection after hands 301 and 302 have moved to the outside of bothracks 200 in the X-Y plane. Besides, hands 301 and 302 are elevated insample measurement apparatus 10 after hands 301 and 302 have moved tothe outside of both racks 200 in the X-Y plane as in the case of stepsS102 to S105, except when hands 301 and 302 pick up sample container 100from rack 200. Thus, it is possible to prevent a situation where, whenhands 301 and 302 are being elevated, hands 301 and 302 come intocontact with sample container 100 stored on rack 200 and samplecontainer 100 erroneously drawn in the upward direction.

At step S106, controller 11 determines whether or not all operationsstarted at steps S102, S103, and S105 have finished. When all operationsstarted at steps S102, S103, and S105 have finished, which means thatholder 12 a is positioned at the initial position, the initializationoperation finishes.

Back to FIG. 6, at step S14, controller 11 chooses rack 200 to beprocessed. For example, if racks 200 set on both drawers 31 are yet tobe processed, controller 11 selects rack 200 set on left drawer 31 asthe processing target. If one of racks 200 set on left and right drawers31 is yet to be processed, controller 11 selects rack 200 yet to beprocessed as the processing target. At step S15, controller 11 driveslock unit 40 to lock drawer 31 on which rack 200 to be processed is set.

At step S16, controller 11 obtains an origin of transfer unit 12. To bemore specific, controller 11 causes left-right move unit 61 to move tothe rightmost side, and causes front-rear move unit 62 to move to therearmost side. A sensor detects that left-right move unit 61 ispositioned on the rightmost side, and another sensor detects thatfront-rear move unit 62 is positioned on the rearmost side. When theorigin of transfer unit 12 is obtained, hands 301 and 302 are positionedat position 82 in the X-Y plane. If the processing returns fromlater-described step S22 to step S14, where rack 200 to be processedmoves from the right side to the left side, the processing at step S16to obtain the origin is omitted.

At step S17, controller 11 sets the transfer target at storage position211 of rack 200 to be processed. At step S18, controller 11 moves holder12 a in the X-axis direction and the Y-axis direction to move to a pointin the X-Y plane above storage position 211 of the transfer target.Subsequently, at step S19, controller 11 causes holder 12 a to move downand to move to a point above storage position 211 of the transfertarget, as illustrated in FIG. 4A. In other words, at step S19, holder12 a is positioned above storage position 211 of the transfer targetsuch that the position in the up-down direction of hands 301 and 302 isin alignment with a position which allows hands 301 and 302 to graspbody part 101 of sample container 100 stored at the storage position.

At step S20, controller 11 determines whether or not drawer 31 is lockedon the opposite side of drawer 31 on which rack 200 to be processed isset. If drawer 31 on the opposite side is locked, controller 11 drivesat step S21 lock unit 40 to unlock drawer 31 on the opposite side.

As described above, if rack 200 processed immediately before is set ondrawer 31 on the opposite side, drawer 31 on the opposite side isunlocked after holder 12 a moves to storage position 211 of rack 200currently to be processed. In addition, at steps S24 and S25 to bedescribed later, drawer 31 is unlocked after holder 12 a moves to theinitial position. In other words, after holder 12 a recedes from rack200 finished with the processing, drawer 31 on which rack 200 finishedwith the processing is set is unlocked. This makes it possible toreliably avoid a situation where drawer 31 is erroneously drawn duringthe processing, and hands 301 and 302 and rack 200 come into contactwith one another.

At step S22, controller 11 performs processing on the racks, which isdescribed later. This finishes processing on all sample containers 100stored on rack 200 to be processed, and processing on rack 200 to beprocessed finishes. The processing on the racks is described later withreference to FIGS. 8 and 9.

At step S23, controller 11 determines whether or not rack 200 yet to beprocessed is set on drawer 31 on the opposite side. If rack 200 yet tobe processed is set on drawer 31 on the opposite side, controller 11returns the processing to step S14. After the processing is returned,controller 11 selects at step S14 rack 200 set on drawer 31 on theopposite side as the processing target. Then, controller 11 performsprocessing through steps S15 to S22, as mentioned above.

As described above, processing is not performed on sample containers 100on rack 200 set in drawer 31 on one side until the processing iscompleted on all sample containers 100 on rack 200 set in drawer 31 onthe other side. This makes it possible to freely draw drawer 31 theprocessing of which is yet to be started, and to set rack 200 on thisdrawer 31.

If controller 11 determines at step S23 that rack 200 yet to beprocessed is not set on drawer 31 on the opposite side, controller 11moves at step S24 holder 12 a to the initial position. At step S25,controller 11 unlocks drawer 31 which has been locked because the drawerwas under processing immediately before, and returns the processing tostep S12.

Next, a description is provided for the processing on the racks at stepS22 with reference to flowcharts of FIGS. 8 and 9.

With reference to FIG. 8, controller 11 performs at step S201 a graspingoperation to close hands 301 and 302 at the storage position of thetransfer target, as described with reference to FIGS. 4A and 4B and FIG.5A. Thus, sample container 100 is detected. If there is sample container100, a determination result is YES at step S202. In this case,controller 11 elevates at step S203 holder 12 a, and picks up samplecontainer 100 being grasped from the storage position of the transfertarget. At step S204, controller 11 causes transfer unit 12 to transferpicked-up sample container 100 to position 81. On the other hand, ifthere is no sample container 100, the determination result is NO at stepS202. In this case, controller 11 skips steps S203 to S215 and advancesthe processing to step S216 in FIG. 9.

At step S205, controller 11 determines whether or not the agitationprocessing can be started on sample container 100 positioned at position81. For example, there may be a case where preceding sample measurementis completed and a case where the preceding sample measurement is notcompleted after controller 11 immediately performs the agitationprocessing on sample container 100 positioned at position 81 andtransfers sample container 100 to position 83. A time period from theend of agitation to the start of measurement varies for differentsamples if samples are immediately aspirated when the preceding samplemeasurement is completed and, when the preceding sample measurement isnot completed, samples are not aspirated until the preceding samplemeasurement is completed. This may give rise to a problem thatmeasurement results vary for different samples. For this reason, it isdesirable that each sample can immediately be aspirated after samplecontainer 100 is agitated and sample container 100 is transferred toposition 83.

Thus, at step S205, controller 11 suspends the processing until samplecontainer 100 after agitation is transferred to position 83 and thesample therein can immediately be aspirated. Controller 11 acquires thetiming at which the preceding sample measurement is completed, anddecides the timing to start the agitation processing based on the timingat which the preceding sample measurement is completed. Thus, timeperiods from the end of agitation to the start of measurement are madeequal, making it possible to reduce the variation in the measurementresults.

If the agitation processing is made possible, controller 11 performs atstep S206 the agitation processing on sample container 100 positioned atposition 81. At step S207, controller 11 causes transfer unit 12 totransfer agitated sample container 100 from position 81 to position 82,and causes holder 12 a to descend and then to set sample container 100on container set unit 32. At step S208, controller 11 causes containerset unit 32 to transfer sample container 100 from position 82 toposition 83. At step S209, controller 11 causes piercer 33 to aspirate asample from sample container 100. At step S210, controller 11 startsmeasurement processing on the aspirated sample.

When the measurement processing is started, sample measurement to bedescribed later is performed. After that, analysis processing to bedescribed later is performed based on the measurement results of themeasurement processing. Controller 11 determines whether or not a retestis necessary based on the results of the analysis processing. Themeasurement processing, the analysis processing, and the determinationas to whether or not a retest is necessary are performed in parallelwith other processing. A description is provided later for themeasurement processing and the analysis processing with reference toFIGS. 10A and 10B.

At step S211, controller 11 causes container set unit 32 to transfersample container 100, finished with aspiration, from position 83 toposition 82. At step S212, controller 11 causes hands 301 and 302 tograsp sample container 100 positioned at position 82, to elevate holder12 a, and to pick up sample container 100 being grasped from containerset unit 32.

At step S213, controller 11 causes holder 12 a to move in the X-axisdirection and the Y-axis direction, and to move to a point in the X-Yplane above the storage position of the transfer target. Subsequently,at step S214, controller 11 causes holder 12 a to move down and to moveto a point above the storage position of the transfer target. To be morespecific, at step S214, holder 12 a is positioned above the storageposition of the transfer target such that the position in the up-downdirection of hands 301 and 302 is one which allows sample container 100being grasped to be stored at the storage position of the transfertarget. Here, the position in the up-down direction of hands 301 and 302is the same as the position which allows hands 301 and 302 to grasp bodypart 101 of sample container 100 stored at the storage position. Thus,as illustrated in FIG. 4B, sample container 100 is returned to theoriginal storage position of original rack 200. At step S215, controller11 causes hands 301 and 302 to open, thereby releasing the grasping ofsample container 100.

With reference to FIG. 9, at step S216, controller 11 determines whetheror not the aspiration of all samples on rack 200 to be processed hasfinished. If the aspiration has not finished for all samples, controller11 determines at step S217 whether or not the transfer target is storageposition 215. In other words, at step S217, controller 11 determineswhether or not there is a storage position yet to be set as the transfertarget on the same row as that of the storage position of the currenttransfer target.

If the determination is NO at step S217, in other words, if the transfertarget is not storage position 215, controller 11 sets at step S218 theleft adjacent storage position as the transfer target. At step S219,controller 11 causes holder 12 a to move to a point above the storageposition of the transfer target. After that, the processing is returnedto step S201 of FIG. 8.

Here, a description is provided for a case where it is determined atstep S217 that the transfer target is not storage position 215 after itis determined at step S202 that there is no sample container 100 at thestorage position of the transfer target.

In this case, at step S219, holder 12 a is sent to a point above theleft adjacent storage position along the shortest path without beingtransferred along an unnecessary path, for example, being moved in theup-down direction. To be more specific, as illustrated in FIG. 4A, whilethe position in the up-down direction of hands 301 and 302 is set at theposition which allows hands 301 and 302 to grasp body part 101 of samplecontainer 100 stored at the storage position, holder 12 a is sent in thenegative X-axis direction. Then, after the processing is returned tostep S201, determination is made as to whether or not there is samplecontainer 100 at the storage position of the transfer target. Thus, ifthere is no sample container 100 at the storage position of the transfertarget, holder 12 a is sequentially sent to a point above the nextstorage position without tracing an unnecessary path, and searches forsample container 100 at the storage position of the transfer target.Hence, it is possible to efficiently transfer sample container 100 toprocessing unit 14, and to improve sample processing efficiency.

In this case, after hands 301 and 302 are opened as a result of thedetermination that there is no sample container 100 at the storageposition of the transfer target, controller 11 causes at step S219 hands301 and 302 to move to a point above the left adjacent storage positionwith hands 301 and 302 not elevated but opened. Since hands 301 and 302are not elevated, this eliminates the necessity of supplying a pressureto cylinder 62 b for elevating hands 301 and 302. Thus, it is possibleto save air provided by pneumatic pressure source 15.

In this case, at step S219, holder 12 a is sent to a point above theleft adjacent storage position along the shortest path, but the path isnot limited to the above one. Holder 12 a may be moved to a point abovethe left adjacent storage position by being moved upward, leftward, anddownward. Also in this case, the transfer path of holder 12 a is shortercompared to the case where holder 12 a is moved to a point above theleft adjacent storage position after holder 12 a is transferred toagitation unit 14 a or measurement unit 14 b of processing unit 14.Thus, it is possible to improve sample processing efficiency. Asdescribed above, sample processing efficiency can sufficiently beimproved even if holder 12 a is directly sent to a point above the leftadjacent storage position along, for example, a path traced upward,leftward, and downward as well as the above-mentioned shortest path. Theword “directly” may include, as described above, the transfer of holder12 a to a point above the next storage position newly set at step S210without diverting holder 12 a from the same row as that of the storageposition of the transfer target.

If the determination is YES at step S217, in other words, if thetransfer target is storage position 215, controller 11 sets at step S220storage position 216 as the transfer target. At step S221, controller 11obtains the origin of transfer unit 12 as in the case of step S16 ofFIG. 6.

At step S222, controller 11 causes holder 12 a to move in the X-axisdirection and the Y-axis direction, and to move to a point in the X-Yplane above storage position 216 of the transfer target. Subsequently,at step S223, controller 11 causes holder 12 a to move down and to moveto a point above storage position 216 of the transfer target, asillustrated in FIG. 4A. To be more specific, at step S223, holder 12 ais positioned above storage position 216 of the transfer target suchthat the position in the up-down direction of hands 301 and 302 is inalignment with a position which allows hands 301 and 302 to grasp bodypart 101 of sample container 100 stored at the storage position. Afterthat, the processing is returned to step S201, and determination is madeas to whether or not there is sample container 100 at storage position216 of the transfer target.

Thus, controller 11 sequentially detects whether or not there is samplecontainer 100 for all storage positions, and if there is samplecontainer 100 at a storage position, controller 11 aspirates a samplefrom this sample container 100. Then, when aspiration of all samples onrack 200 to be processed finishes, controller 11 makes a determinationYES at step S216, and advances the processing to step S224.

At step S224, controller 11 determines whether or not all retestdeterminations and necessary retests have finished for all samples onrack 200 to be processed. If the determination at step S224 is NO, inother words, if not all retest determinations and necessary retests havefinished, controller 11 determines at step S225 whether or not there aresamples that may require a retest, based on analysis results of theinitial test. If there are samples that may require a retest, controller11 performs at step S226 measurement processing for retest on thesamples that may require a retest in the same procedures as those of theabove-described initial test. To be more specific, after the agitationprocessing is performed, sample container 100 determined to require aretest is transferred to position 83. Then, the sample inside samplecontainer 100 is aspirated and the measurement processing is performedagain on the sample. When aspiration for retest finishes, samplecontainer 100 is returned to the original storage position.

If the determination at step S224 is YES, in other words, if all retestdeterminations and necessary retests have finished, the processing onthe rack finishes and the processing is advanced to step S23 of FIG. 6.

As illustrated in FIG. 10A, when the measurement processing is started,controller 11 causes at step S301 specimen preparation unit 34 toprepare a measurement specimen based on the aspirated sample. At stepS302, controller 11 allows the prepared measurement specimen to flowinto flow cell 35 a. At step S303, controller 11 causes detector 35 toirradiate the measurement specimen flowing through flow cell 35 a with alaser beam, thereby acquiring optical information based on forwardscattered light, side scattered light, and fluorescent light producedfrom particles contained in the measurement specimen.

Here, sample measurement apparatus 10 has a DIFF measurement mode formeasuring white blood cells, a RET measurement mode for measuringreticulocytes, and a PLT measurement mode for measuring platelets.Controller 11 sequentially performs the processing of steps S301 to S303for each measurement mode. When the processing of steps S301 to S303 foreach measurement mode finishes, controller 11 starts at step S304 theanalysis processing.

As illustrated in FIG. 10B, when the analysis processing is started,controller 11 creates at step S401 scattergrams illustrated in FIGS. 11Ato 11C based on the results obtained in the measurement processing. Atstep S402, controller 11 acquires analysis results such as the number ofblood cells based on the created scattergrams.

Both the measurement processing and the analysis processing areperformed by sample measurement apparatus 10, but the embodiment is notlimited to the above. The configuration may be such that samplemeasurement apparatus 10 performs a transfer operation to pick up samplecontainer 100 from rack 200 and to transfer the sample container toposition 82, and both the measurement processing and the analysisprocessing are performed by another apparatus. Alternatively, theconfiguration may be such that sample measurement apparatus 10 performsthe transfer operation and the measurement processing, and the analysisprocessing is performed by another apparatus.

Note that controller 11, and the like in sample measurement apparatus 10are implemented such that, for example, a circuitry such as one or morecentral processing units (CPUs) or processors provided in samplemeasurement apparatus 10 executes a predetermined program(s).

According to one or more embodiments, it is possible to improve sampleprocessing efficiency.

While various embodiments of the present invention have been describedabove, it should be understood that they have been presented by way ofexample only and not limitation. Numerous changes to the disclosedembodiments can be made in accordance with the disclosure herein withoutdeparting from the spirit or scope of the invention. Thus, the breadthand scope of the present invention should not be limited by any of theabove described embodiments. Rather, the scope of the invention shouldbe defined in accordance with the following claims and theirequivalents.

The invention claimed is:
 1. A sample measurement apparatus capable ofprocessing a sample or samples stored in a sample container or samplecontainers stored on a rack, the apparatus comprising: a controllerprogrammed to perform control; a processing unit that aspirates thesample stored in the sample container and measures the sample, under thecontrol of the programmed controller; a transfer unit that includes aholder to hold the sample container, and that picks up and transfers,under the control of the programmed controller, the sample containerfrom the rack capable of storing one or more of the sample containers atstorage positions on a row to the processing unit; a detection unit thatis attached to the holder and is movable integrally with the holder; andwherein the holder includes: a first claw; a second claw; and anopen-close mechanism to open and close the first claw and the secondclaw under the control of the programmed controller, wherein thecontroller is programmed to control the detection unit to detect apresence or an absence of the sample container at a storage positionbased on a distance between the first and second claws in a case of theopen-close mechanism closing the first and second claws, the distancevarying with or without the sample container between the first andsecond claws, wherein the controller is programmed to control thetransfer unit to transfer one or more of the sample containers stored onthe rack one by one, the storage positions include a first storageposition and a second storage position, in a case of the detection unitbeing located at a point above the first storage position and detectingthat the sample container is at the first storage position, thecontroller is programmed to control the transfer unit to transfer thedetected sample container from the first storage position to theprocessing unit, and in a case of the detection unit being located atthe point above the first storage position and detecting that the samplecontainer is not at the first storage position, the controller isprogrammed to control the holder to directly move from the point abovethe first storage position to a point above the second storage position,and is programmed to control the detection unit to detect whether thereis another sample container at the second storage position.
 2. Thesample measurement apparatus according to claim 1, wherein the secondstorage position is arranged on the same row as the first storageposition.
 3. The sample measurement apparatus according to claim 1,wherein the row of the storage positions includes a plurality of rows,and in a case of the absence of the second storage position on a firstrow of the plurality of rows, the controller is programmed to set apredetermined storage position on a second row of the plurality of rowsas a second storage position on the second row and is programmed tocontrol the holder to move to the point above the second storageposition on the second row, and is programmed to control the detectionunit to detect whether there is a sample container at the second storageposition on the second row.
 4. The sample measurement apparatusaccording to claim 1, wherein the storage positions include more thantwo storage positions, and the first storage position is adjacent to thesecond storage position among the storage positions on the rack, and ina case of the detection unit detecting that there is no sample containerat the first storage position, the controller is programmed to controlthe holder to move to the point above the second storage positionadjacent to the first storage position, and is programmed to control thedetection unit to detect whether there is a sample container at thesecond storage position.
 5. The sample measurement apparatus accordingto claim 1, wherein the holder includes two hands and each of the firstand second claws are respectively attached to one of the two hands; thecontroller is programmed to control the hands to move upward anddownward, and in a case of the holder being moved to the first storageposition and the detection unit detecting that there is no samplecontainer at the first storage position, the controller is programmed tocontrol the hands to move to the second storage position with the handsnot moved upward but opened.
 6. The sample measurement apparatusaccording to claim 5, wherein the controller is programmed to controlthe hands to move upward or downward, the hands being outside on therack, and the controller is programmed to control the hands to moveupward to pick up a sample container from a rack, the hands being insideon the rack.
 7. The sample measurement apparatus according to claim 1,further comprising a first drawer to which a first rack is installed anda second drawer to which a second rack is installed, wherein thecontroller is programmed to control the transfer unit to transfer one ormore sample containers on the second rack installed to the second draweruntil transferring all of one or more sample containers on the firstrack installed to the first drawer is completed.
 8. The samplemeasurement apparatus according to claim 7, further comprising lockunits that lock the first drawer and the second drawer, respectively,wherein the controller is programmed to control the respective lock unitto unlock the first drawer after controlling the holder to recede fromthe first rack installed to the first drawer.
 9. The sample measurementapparatus according to claim 1, wherein the processing unit includes ameasurement unit that measures a sample stored in a sample container andan agitation unit that performs an agitation operation on a samplecontainer storing a sample, and the controller is programmed to controlthe transfer unit to transfer a sample container storing a sample fromthe rack to the measurement unit via the agitation unit.
 10. The samplemeasurement apparatus according to claim 9, wherein in a case of themeasurement unit measuring a sample stored in a different samplecontainer, the controller is programmed to control the agitation unit tostart the agitation operation based on a completion timing of ameasurement of the sample stored in the different sample container. 11.The sample measurement apparatus according to claim 1, wherein in a caseof the holder being at a predetermined position, the controller isprogrammed to skip an initialization operation on the transfer unit. 12.The sample measurement apparatus according to claim 3, wherein theholder includes two hands and each of the first and second claws arerespectively attached to one of the two hands; the controller isprogrammed to control the hands to move upward and downward, and in acase of the holder being moved to the first storage position and thedetection unit detecting that there is no sample container at the firststorage position, the controller is programmed to control the hands tomove to the second storage position with the hands not moved upward butopened.
 13. The sample measurement apparatus according to claim 4,wherein the holder includes two hands and each of the first and secondclaws are respectively attached to one of the two hands; the controlleris programmed to control the hands to move upward and downward, and in acase of the holder being moved to the first storage position and thedetection unit detecting that there is no sample container at the firststorage position, the controller is programmed to control the hands tomove to the second storage position with the hands not moved upward butopened.
 14. The sample measurement apparatus according to claim 3,further comprising a first drawer to which a first rack is installed anda second drawer to which a second rack is installed, wherein thecontroller is programmed to control the transfer unit to transfer one ormore sample containers on the second rack installed to the second draweruntil transferring all of one or more sample containers on the firstrack installed to the first drawer is completed.
 15. The samplemeasurement apparatus according to claim 4, further comprising a firstdrawer to which a first rack is installed and a second drawer to which asecond rack is installed, wherein the controller is programmed tocontrol the transfer unit to transfer on one or more sample containerson the second rack installed to the second drawer until transferring allof one or more sample containers on the first rack installed to thefirst drawer is completed.
 16. The sample measurement apparatusaccording to claim 1, wherein the detection unit includes: an operatingunit attached to one of the first claw and the second claw andconfigured to move together with an open-close operation of one of thefirst claw and the second claw; and a detector to detect whether theoperating unit is brought to a detection position, wherein the operatingunit is not detected to be at the detection position in a state in whichthe first claw and the second claw are closed with a presence of asample container therebetween, and the operating unit is detected to beat the detection position in a state in which the first and second clawsare closed without a sample container therebetween, and thereby thedetection unit recognizes a presence of a sample container at one of thestorage positions on the rack.